The present invention relates to an ellipse drawing instrument with which ellipses of varying size and angle can be drawn accurately and efficiently.
The necessity of drawing ellipses often arises in drafting drawings, illustrations or the like. Conventionally, ellipses have been drawn either by use of a set of ellipse rules made by punching ellipses in thin plates or by use of a rule and a pair of compasses.
Ellipse rules, the edge of which is traced with a writing implement to draw ellipses, provide a handy tool, but have several shortcomings. Since a lot of rules have to be kept on hand to cover ellipses of different sizes and angles, this method entails a considerable cost. Also, even if a complete set of rules is purchased, only a limited number of ellipses can be drawn since such rules differ in size and angle in a steplike manner.
The other method using compasses and ordinary rules requires considerable skill or technique and takes much time because the ratio between the lengths of the major and minor axes has to be calculated for each ellipse.